SYNAPTOGENESIS IN VISUAL-CORTEX OF NORMAL AND PRETERM MONKEYS - EVIDENCE FOR INTRINSIC REGULATION OF SYNAPTIC OVERPRODUCTION
SYNAPTOGENESIS IN VISUAL-CORTEX OF NORMAL AND PRETERM MONKEYS - EVIDENCE FOR INTRINSIC REGULATION OF SYNAPTIC OVERPRODUCTION
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DOI：
10.1073/pnas.86.11.4297
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发表时间：
1989-06-01
影响因子：
11.1
通讯作者：
RAKIC, P
中科院分区：
文献类型：
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作者：
BOURGEOIS, JP;JASTREBOFF, PJ;RAKIC, P
我们使用定量电子显微镜来确定早熟视觉经验对恒河猴原始视皮层中突触过度产生的时间进程、程度和模式的影响。胎儿在足月前3周通过剖宫产出生，暴露在正常的光照强度和昼夜周期下，并在出生后第一个月内死亡，并与足月分娩的年龄匹配的对照组一起出生。我们发现，过早的视觉刺激不会影响突触增加和生产过剩的速度。这两个过程都与受孕时间有关，而不是与分娩时间有关。相反，早产儿和对照组的突触的大小、类型和板层分布明显不同。这些参数的变化和差异与视觉刺激的持续时间相关，并随着年龄的增长而变得不那么明显。如果婴儿期的视觉经验影响视皮层的成熟，那么这种影响主要是通过加强、修改和/或消除已经形成的突触，而不是通过调节突触产生的速度来实现的。
We used quantitative electron microscopy to determine the effect of precocious visual experience on the time course, magnitude, and pattern of perinatal synaptic overproduction in the priamry visual cortex of the rhesus monkey. Fetuses were delivered by caesarean section 3 weeks before term, exposed to normal light intensity and day/night cycles, and killed within the first postnatal month, together with age-matched controls that were delivered at term. We found that premature visual stimulation does not affect the rate of synaptic accretion and overproduction. Both of these processses proceed in relation to the time of conception rather than to the time of delivery. In contrast, the size, type, and laminar distribution of synapses were significantly different between preterm and control infants. The changes and differences in these parameters correlate with the duration of visual stimulation and become less pronounced with age. If visual experience in infancy influences the maturation of the visual cortex, it must be so predominantly by strengthening, modifying, and/or eliminating synapses that have already been formed, rather than by regulating the rate of synapse production.